| Value | Category | Cases | |
|---|---|---|---|
| -99 | Don't know | 0 |
0%
|
| -9 | Don't know (spontaneous) | 9 |
0.9%
|
| 1 | Yes | 47 |
4.8%
|
| 2 | No | 919 |
94.3%
|
| Sysmiss | 394 |